A client is admitted to the emergency department with a suspected myocardial infarction. Which laboratory test should the nurse prioritize to confirm the diagnosis?

Choice A reason: Using a soft foam collar may reduce skin irritation but risks dislodging the tracheostomy tube if not secured properly. Leaving old ties in place until new ones are secure ensures tube stability, preventing accidental decannulation, which is critical in early tracheostomy care.

Choice B reason: Knots close to the tracheostomy tube increase pressure on the skin, risking irritation or necrosis. This is incorrect, as ties should allow slight movement. Maintaining old ties until new ones are secure prevents tube displacement, prioritizing airway safety during the procedure.

Choice C reason: Leaving old ties in place until new ones are secure prevents tracheostomy tube dislodgement, a life-threatening risk. This ensures continuous airway patency during tie changes, especially in fresh tracheostomies, making it the safest and most critical action to maintain tube stability.

Choice D reason: Placing knots laterally reduces irritation but does not address the risk of tube dislodgement during tie changes. Keeping old ties in place until new ones are secure is the priority, as it ensures the tube remains stable, preventing airway compromise.

Choice A reason: Hemoccult tests detect blood in sputum, indicating hemoptysis, a TB symptom, but do not confirm Mycobacterium tuberculosis infection. Sputum culture is required for definitive diagnosis, as hemoccult only identifies bleeding, which is nonspecific and can occur in other respiratory conditions.

Choice B reason: Chest x-ray or CT scans show pulmonary abnormalities like cavitary lesions in TB but are not confirmatory. Radiographic findings suggest TB but require microbiological confirmation via sputum culture, as similar patterns occur in other lung diseases, making imaging supportive but not diagnostic.

Choice C reason: Sputum culture positive for Mycobacterium tuberculosis is the gold standard for TB diagnosis. It directly identifies the pathogen, confirming active infection. Other tests like skin tests or imaging are suggestive but not definitive, as they cannot distinguish active TB from latent or other conditions.

Choice D reason: A positive PPD skin test indicates TB exposure or latent infection but does not confirm active disease. False positives occur with prior BCG vaccination or nontuberculous mycobacteria. Sputum culture is needed to verify active TB, making the skin test less definitive.